Technical Abstract:
Peach germplasm is rich in diversity for plant growth habit. Most of the growth habits in peach are the result of single gene changes and can be readily manipulated by breeders. In spite of this fact, there has been relatively little effort to genetically alter peach tree growth habit. The peach industry suffers from low productivity and lacks efficient high-density production systems as exist for apple. Alternate tree growth habits could be at least part of the solution for increasing peach productivity while maintaining high fruit quality. The characteristics of various novel peach tree growth habits have been demonstrated. Columnar and upright trees are particularly promising growth types for high-density production systems, and several new cultivars have been recently released for grower tests. Narrow-leaf trees that allow increased light penetration into the canopy and are more water use efficient also appear promising. Spur-type trees could change the way that peaches are grown and drastically reduce pruning. In the future, growers may have an array of high quality and productive peach varieties available with growth habits such as columnar, upright, spur, semi-dwarf, or narrow-leaf, that are suited to their particular needs and capabilities.